The (almost) ideal thermodynamics of aqueous rubidium nitrite solutions from 0.3 to 62.3 molal

Abstract

Previous works have assumed aqueous electrolyte solutions behave thermodynamically non-ideal. When modeling the RbNO2-H2O system, it was found that the enthalpy of liquification was zero, which would be a characteristic of an ideal system. Plotting the water mole fraction versus the water activity confirmed that this system was almost ideal (just 5% difference at 62.3 molal). RbNO2 solutions thus provide insight into ideality in aqueous solutions. An important characteristic of RbNO2 that may account for the ideality may be that RbNO2′s attraction for water is nearly identical as the attraction of water to other water molecules.